1. Field of the Invention
The present invention is directed to a refreshable display system with an flexible surface, with one application being a refreshable Braille display systems for use as a monitor for computer systems.
2. Technology Review
The flourishing computer and information revolution has left behind visually impaired and particularly visually and hearing impaired individuals. This is due to the fact that visual display units, typically cathode ray tubes (CRTs), are the heart of all modern communication and information systems including the Internet. This especially affects those impaired individuals in the technical fields. To remedy this situation and promote the Americans with Disabilities Act that mandates equal access and opportunities be presented to all capable individuals, Congress has proposed a State Model Bill. The bill would provide materials in a computer-accessible format capable of Braille reproduction. It states, xe2x80x9cthe Legislature finds that:
(1) the advent of the information age throughout the United States and around the world has resulted in lasting changes in information technology;
(2) use of interactive visual display terminals by state and state-assisted organizations is becoming a widespread means of access for employees and the public to obtain information available electronically, but nonvisual access, whether by speech, Braille, or other appropriate means has been overlooked in purchasing and deploying the latest information technology;
(3) presentation of electronic data solely in a visual format is a barrier to access by individuals who are blind or visually impaired, preventing them from participating on equal terms in crucial areas of life, such as education and employment;
(4) alternatives, including both software and hardware adaptations, have been created so that interactive control of computers and use of the information presented is possible by both visual and nonvisual means; and
(5) the goals of the state in obtaining and deploying the most advanced forms of information technology properly include universal access so that segments of society with particular needs (including individuals unable to use visual displays) will not be left out of the information age.
Prior art computer interfaced Braille devices use various mechanisms to actuate the Braille dots and xe2x80x9crefreshxe2x80x9d the text. The dots are controlled via macroscopic actuators comprised of piezoelectric materials, shape memory alloys, and solenoids to raise individual pins in the Braille cells. Most of these devices display one or two lines and up to 80 Braille cells per row. Ideally, more rows of Braille text are desired, however, the complexity of the actuators and the close spacing of the Braille dots limit the number of Braille cells and increase the costs. Such actuators also require a very large xe2x80x9cvolume overheadxe2x80x9d to accommodate this complex network of actuators and wires needed to operate the Braille dots. The result is that the foot print of the unit is much larger than the display surface and it is difficult to skim information based on the limited number of Braille cells.
Recently, a company in Cambridge, Mass. called Braille Displays overcame this limitation of only being able to produce a Braille display with two rows of Braille cells. This company with the support of the National Science Foundation was able to produce a prototype 4 line by 40 column prototype refreshable Braille display. This 160 cell display is not commercially available partially due to the costs and the difficulty of integrating large numbers of actuators in a manufacturing process. Telesensory another company in this area produces an 80 character unit, PowerBraille 80 (PB 80). This device has many user friendly features integrated into its device such as a cursor locator, a touch sensitive strip and scrolling toggle.
U.S. Pat. No. 5,685,721, to Decker, discloses a macro-sized shape-memory alloy based actuator enclosed in a series of tubes and housed in modules which are mounted into a multi-row display under ledges. U.S. Pat. No. 5,685,721, to Vuyk, discloses another macro-sized actuation technique utilizing an intrinsically conducting polymer sheet that expands when a charge is applied. Another macro-sized actuation technique, utilizing a rotary actuator with cams is disclosed by U.S. Pat. No. 5,453,012, to Hudecek. Also, Garner, U.S. Pat. No. 5,496,174 utilizes an electrorheological fluid that expands when a high voltage is applied. All of these devices suffer from one or more of the same fundamental problems: a large number of individual components needed for each Braille dot increasing assembly problems; high power requirements eliminating the potential for portability and creating problems dissipating the excess heat; responding fast enough to allow refresh rates appropriate for computer based communications; the difficulties in assembling the large number of Braille dots needed for true replication of computer display terminals; and the costs of manufacturing such displays.
Another approach to providing access to the visually impaired has been the development of optical recognition systems attached to voice synthesizers. Although these devices represent an enormous leap forward in access to both computerized and printed material, they are not appropriate for all tasks. Specifically, they cannot be used with detailed technical material, which has a very specialized vocabulary. Medicine, law, accounting, engineering, and science careers are restricted by this limitation. Voice synthesizing devices are not effective at dealing with tabular material. The voice synthesizing devices do not provide blind accountants and bookkeepers the access they require to spreadsheets and databases. Furthermore, voice synthesizers are not capable of limited document skimming, or provide a means to address accessing links otherwise known as sub-directories or complementary subject indicators. Perhaps most important, these reading devices provide limited ability to edit text or tables.
The devices currently available for the sight impaired are limited and have drawbacks in that they do not have fast enough refresh rate or sufficient Braille character ability to replicate a computer display, including memory capacity, readable area, and scanning and highlighting functions; are bulky and heavy; can not be adapted for different applications, i.e., a lap top vs. a desk top computer, cannot xe2x80x9cdisplayxe2x80x9d technical, accounting, spreadsheets, or other specialized forms of display which are not a basic textual document; and are expensive to manufacture.
Accordingly, a need exists for a refreshable Braille display that overcomes the above mentioned limitations and drawbacks.
The present invention is further directed to a refreshable display system with a flexible surface, with one application being a refreshable Braille display systems for use as a monitor for computer systems.
In one embodiment, the present invention includes a refreshable Braille display system or a module in such a system comprising a) a plurality of microelectromechanical valves having a top surface and a bottom surface, each microelectromechanical valves having an opening or positioned in line with an opening each of which represents a Braille dot and each opening arranged in a pattern of Braille cells with the Braille cells forming a Braille display; and b) an elastomeric polymer having a upper and a lower surface, the lower surface of the elastomeric polymer being sealed about each opening which represent the Braille dots; wherein during operation of the display system the upper surface of the elastomeric polymer forms a plurality of Braille dots which are extended and retracted based upon the operation of the electromechanical valves.
In another embodiment, the present invention includes a refreshable Braille display system or a module in such a system comprising a) a plurality of microelectromechanical piezoelectric based devices having a top surface and a bottom surface, each microelectromechanical piezoelectric based device having an opening or positioned in line with an opening each of which represents a Braille dot and each opening arranged in a pattern of Braille cells with the Braille cells forming a Braille display; and b) an elastomeric polymer having a upper and a lower surface, the lower surface of the elastomeric polymer being sealed about the openings which represent the Braille dots; wherein during operation of the display system the upper surface of the elastomeric polymer forms a plurality of Braille dots which are extended and retracted based upon the operation of the electromechanical piezoelectric based devices.
In another embodiment, the present invention includes a refreshable Braille display system or a module in such a system comprising a) a plurality of microelectromechanical shape memory alloy based devices having a top surface and a bottom surface, each microelectromechanical shape memory alloy based device having an opening or positioned in line with an opening each of which represents a Braille dot and each opening arranged in a pattern of Braille cells with the Braille cells forming a Braille display; and b) an elastomeric polymer having a upper and a lower surface, the lower surface of the elastomeric polymer being sealed about the openings which represent the Braille dots; wherein during operation of the display system the upper surface of the elastomeric polymer forms a plurality of Braille dots which are extended and retracted based upon the operation of the electromechanical shape memory alloy based devices.
Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the description serve to explain the principles and operation of the invention.